Dinghy for tall man with sore back?!?

You're probably too heavy for a Vortex in any case. Don't know what difference the kite has made but when I had one (and was 80kg) the top guys were all in the 65-70kg range. And they're mainly in Yorkshire. And when the wind too light to trapese you have to weave yourself in and out of the shrouds and lowers with a tiller extension that bends as soon as you give it a hard stare.

Trapese is definitely best way to preserve a bad back. When Laser sailing I'd be visiting the osteopath at regualr intervals. Since trapesing my back has been fine. Although I have put on 10kg as a result of the reduced exercise (at least that's my excuse).

Dart15?

How about a phantom

a laser for big lads. Older examples in VGC under a grand.

  Reckon you would be too big for a solo, even a bit cramped but there will probably be lots of solo owners disputing this

Hiking is no doubt a lot better training for your torso stability than trapezing!

ALl this McKenzie inverting your spine stuff seems to have gone out in favour of palates torso and balance builders- done my back wonders. Get a joint qulaified physio-chiro,  a rare breed, or two one from each type,  who cooperate on sports injuries.

My husband will only trapeze because of his back so either crews me in an Osprey or helms a Contender when I am not available.

However, he really enjoyed borrowing a Supa Nova for an afternoon, compared to our sons' laser. Much more comfortable and forgiving.

Trolleys can often be adapted to add a jockey wheel - they don't necessarily always come with one in a class.  Also balancing the boat correctly on a trolley will help the weight issue.

The Contender is an option but perhaps not the best one:-

Fairly heavy.  Any spare bodies on board tend to get clouted with the tiller extension eventually (nowhere in the cockpit is safe!) and of course the low boom. You can get a sail altered as there is no minimum leach length though. Best talk to some of the Contenderers at Portishead if you're still keen.